Mailing List Archive: Varnish: Misc

HA with Varnish? advice request

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cdgraff at gmail

Dec 6, 2011, 7:05 PM

Post #1 of 4 (382 views)
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HA with Varnish? advice request

Hi guys,

I need your advice... I'm using varnish into multiple server, some for
caching dynamic content and other only for static content.

On front of the Dynamic Content Varnish y have Cisco ACE Load balancer, but
on front of the Static Varnish, the traffic is much higher and can't use
Cisco ACE, for this reason I'm using RoundRobin DNS into this 2 servers.

This week I had, some network issue with one of this servers and when the
network go down I loose 50% of the traffic...

here my question, or advice request... How I can have HA with 2 varnish
server? I'm thinking on Heartbeat or Heartbeat+ldirectord, please fell free
to send your suggestions.

Sorry for my English and regards from Argentina

Alejandro

allan_wind at lifeintegrity

Dec 6, 2011, 9:34 PM

Post #2 of 4 (372 views)
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Re: HA with Varnish? advice request [In reply to]

On 2011-12-07 00:05:24, Alejandro wrote:
> Hi guys,
>
> I need your advice... I'm using varnish into multiple server, some for
> caching dynamic content and other only for static content.
>
> On front of the Dynamic Content Varnish y have Cisco ACE Load balancer, but
> on front of the Static Varnish, the traffic is much higher and can't use
> Cisco ACE, for this reason I'm using RoundRobin DNS into this 2 servers.
>
> This week I had, some network issue with one of this servers and when the
> network go down I loose 50% of the traffic...
>
> here my question, or advice request... How I can have HA with 2 varnish
> server? I'm thinking on Heartbeat or Heartbeat+ldirectord, please fell free
> to send your suggestions.

As your clients do not fall back to the 2nd IP it means you need
one (active/passive) or two vips (active/active) that can be
shared between your two varnish servers.

If you have cachable dynamic content then your two Varnish
instances may return different content to the same client. This
may or may not be an issue. Others will have to weight in if
cache invalidation of Varnish entries is a doable strategy
(if you cannot set your expiration headers correctly). On the
positive side you have a warm cache should one of your Varnish
instances fail. With a active/passive fail over the cold cache
may be problematic.

That said I am surprised that you think Varnish will be able to
handle your traffic but a pair of load balancers cannot. If the
Cisco ACE is not up to it have you looked at haproxy? You still
have the same vip issues, but load balancers are stateless and
give you persistence connections to minimize differences between
Varnish instances.

/Allan
--
Allan Wind
Life Integrity, LLC
<http://lifeintegrity.com>

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john at 8t8

Dec 6, 2011, 10:54 PM

Post #3 of 4 (365 views)
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Re: HA with Varnish? advice request [In reply to]

I'm succesfully using lvs in director mode to load balance and provide ha
for multiple varnish caches. It works really well.
On Dec 7, 2011 5:36 a.m., "Allan Wind" <allan_wind [at] lifeintegrity> wrote:

> On 2011-12-07 00:05:24, Alejandro wrote:
> > Hi guys,
> >
> > I need your advice... I'm using varnish into multiple server, some for
> > caching dynamic content and other only for static content.
> >
> > On front of the Dynamic Content Varnish y have Cisco ACE Load balancer,
> but
> > on front of the Static Varnish, the traffic is much higher and can't use
> > Cisco ACE, for this reason I'm using RoundRobin DNS into this 2 servers.
> >
> > This week I had, some network issue with one of this servers and when the
> > network go down I loose 50% of the traffic...
> >
> > here my question, or advice request... How I can have HA with 2 varnish
> > server? I'm thinking on Heartbeat or Heartbeat+ldirectord, please fell
> free
> > to send your suggestions.
>
> As your clients do not fall back to the 2nd IP it means you need
> one (active/passive) or two vips (active/active) that can be
> shared between your two varnish servers.
>
> If you have cachable dynamic content then your two Varnish
> instances may return different content to the same client. This
> may or may not be an issue. Others will have to weight in if
> cache invalidation of Varnish entries is a doable strategy
> (if you cannot set your expiration headers correctly). On the
> positive side you have a warm cache should one of your Varnish
> instances fail. With a active/passive fail over the cold cache
> may be problematic.
>
> That said I am surprised that you think Varnish will be able to
> handle your traffic but a pair of load balancers cannot. If the
> Cisco ACE is not up to it have you looked at haproxy? You still
> have the same vip issues, but load balancers are stateless and
> give you persistence connections to minimize differences between
> Varnish instances.
>
>
> /Allan
> --
> Allan Wind
> Life Integrity, LLC
> <http://lifeintegrity.com>
>
> _______________________________________________
> varnish-misc mailing list
> varnish-misc [at] varnish-cache
> https://www.varnish-cache.org/lists/mailman/listinfo/varnish-misc
>

cdgraff at gmail

Dec 7, 2011, 6:13 AM

Post #4 of 4 (371 views)
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Re: HA with Varnish? advice request [In reply to]

Thanks guys for the answers...

I try to create, Active/Active model... I'll check this soft like wackamole
or director...

2011/12/7 john [at] 8t8 <john [at] 8t8>

> I'm succesfully using lvs in director mode to load balance and provide ha
> for multiple varnish caches. It works really well.
> On Dec 7, 2011 5:36 a.m., "Allan Wind" <allan_wind [at] lifeintegrity>
> wrote:
>
>> On 2011-12-07 00:05:24, Alejandro wrote:
>> > Hi guys,
>> >
>> > I need your advice... I'm using varnish into multiple server, some for
>> > caching dynamic content and other only for static content.
>> >
>> > On front of the Dynamic Content Varnish y have Cisco ACE Load balancer,
>> but
>> > on front of the Static Varnish, the traffic is much higher and can't use
>> > Cisco ACE, for this reason I'm using RoundRobin DNS into this 2 servers.
>> >
>> > This week I had, some network issue with one of this servers and when
>> the
>> > network go down I loose 50% of the traffic...
>> >
>> > here my question, or advice request... How I can have HA with 2 varnish
>> > server? I'm thinking on Heartbeat or Heartbeat+ldirectord, please fell
>> free
>> > to send your suggestions.
>>
>> As your clients do not fall back to the 2nd IP it means you need
>> one (active/passive) or two vips (active/active) that can be
>> shared between your two varnish servers.
>>
>> If you have cachable dynamic content then your two Varnish
>> instances may return different content to the same client. This
>> may or may not be an issue. Others will have to weight in if
>> cache invalidation of Varnish entries is a doable strategy
>> (if you cannot set your expiration headers correctly). On the
>> positive side you have a warm cache should one of your Varnish
>> instances fail. With a active/passive fail over the cold cache
>> may be problematic.
>>
>> That said I am surprised that you think Varnish will be able to
>> handle your traffic but a pair of load balancers cannot. If the
>> Cisco ACE is not up to it have you looked at haproxy? You still
>> have the same vip issues, but load balancers are stateless and
>> give you persistence connections to minimize differences between
>> Varnish instances.
>>
>>
>> /Allan
>> --
>> Allan Wind
>> Life Integrity, LLC
>> <http://lifeintegrity.com>
>>
>> _______________________________________________
>> varnish-misc mailing list
>> varnish-misc [at] varnish-cache
>> https://www.varnish-cache.org/lists/mailman/listinfo/varnish-misc
>>
>
> _______________________________________________
> varnish-misc mailing list
> varnish-misc [at] varnish-cache
> https://www.varnish-cache.org/lists/mailman/listinfo/varnish-misc
>

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